310 DISCOVERY OH. xi 



Hospital, and Mr. Harry W. Cox, who were the first 

 martyrs of the rays, and Dr. Hall Edwards, whose left 

 arm had to be removed. Mankind should not forget 

 the names of these and other experimenters by whose 

 sufferings increased knowledge has been attained. 



Operators with X-rays now protect themselves from 

 injury by using screens which shield them, but in the 

 early days the necessity for such precautions was not 

 understood. The rays are now kept under control, and 

 their power of affecting animal tissue is used to cure 

 instead of being harmful. In certain diseased conditions, 

 local application of Rontgen rays has been used with 

 marked success, and the field of their utility will certainly 

 extend as improvements are effected in their technique. 

 Radium has proved to be a valuable agent for the 

 removal of certain ulcers and small cancerous growths, 

 but neither it nor X-rays can at present be looked upon 

 as a cure for cancerous growths of large size. In many 

 cases, radium emanation is more convenient to use than 

 its parent ; for it can be inhaled, and when dissolved 

 can be injected into the body tissues, or swallowed. We 

 are only just beginning to learn something of the bio- 

 logical significance of the new rays ; and no one can yet 

 predict with confidence the beneficial action which the 

 next generation will discover in them. 



